Michigan lawmakers return to the Capitol on Wednesday with major decisions to make on whether to adopt citizen-initiated laws raising the minimum wage and mandating employer-provided paid sick time for workers.

Organizers of a ballot initiative that would raise Michigan's minimum wage to $12 an hour have threatened to sue if the Republican-led Legislature adopts the minimum wage proposal but then weakens it later in the year.

The move would be unconstitutional, One Fair Wage lawyer Mark Brewer said Tuesday at a Capitol news conference.

Lawmakers can only adopt the measure — making it law — or reject it, in which case it would go on the November ballot, Brewer said. Legislators also could propose an alternative to appear on the ballot alongside the proposal.

Crain'sfirst reported Aug. 23 that the Michigan Restaurant Association was pushing for lawmakers to consider adopting the minimum wage increase and then scaling it back for tipped workers.

The Legislature returns Wednesday following a 12-week summer break.

Republicans are expected to discuss using the unprecedented strategy for both the minimum wage initiative and a separate citizens' initiative that would require employers to provide paid sick leave.

Both the House and Senate had the two citizen-led ballot initiatives on their possible agendas for Wednesday's session. They face a deadline this week of deciding whether to adopt the initiatives as law or let voters decide.

A new coalition of business groups — Small Business for a Better Michigan — on Tuesday urged the Legislature to adopt the paid sick time proposal to keep it off the Nov. 6 ballot.

"As with all other laws pertaining to business, it is important to keep policy making within the hands of the policy makers," said Mike Johnston, vice president of government affairs for the Michigan Manufacturers Association, in a statement. "If there are provisions in this proposal that would harm or reverse Michigan's comeback, we need to be able to address them at the legislative level."

The coalition's members include the Small Business Association of Michigan, National Federation of Independent Business, the Auto Dealers of Michigan, the Michigan Soft Drink Association, the Home Builders Association of Michigan, the Michigan Restaurant Association, the Michigan Retailers Association, Associated Builders & Contractors of Michigan, the Michigan Chamber of Commerce and the Detroit Regional Chamber.

The NFIB wants lawmakers to adopt both ballot initiatives on Wednesday so the laws can be more easily amended in the future, said Charles Owens, state director of the small business organization's Michigan chapter.

Under the state constitution, voter-approved laws require a three-fourths super majority of both houses of the Legislature to change the law and override voters — a legislative hurdle that has made amending Michigan's 2008 voter-approved medical marijuana law difficult.

"This will be an impossible requirement to meet and Michigan will be stuck with the most stringent paid sick leave and minimum wage employer mandate in the country," Owens said in a statement.

Under the proposal, the minimum wage for tipped employees would gradually increase from the current $3.52 until reaching the minimum wage for all other workers in 2024. Some restaurateurs say it would reduce others' wages or force restaurant owners to change the business model to remain solvent.